(Reuters) - Unbeaten Nyquist is a prohibitive favorite to add the second jewel of horse racing's Triple Crown at the Preakness Stakes on Saturday, while his top rival hopes rain and a sloppy track at Pimlico will be the equalizer.

Kentucky Derby winner Nyquist is rated a 3-5 odds-on pick from the third post position to keep alive his Triple Crown bid in the 1-3/16 mile race in Baltimore, having out dueled second choice Exaggerator in four previous meetings.

But rain forecast from dawn to dusk on Saturday could muddy the Pimlico picture with Exaggerator having proven he can handle that footing with a decisive victory in the slop at the Santa Anita Derby.

"With a horse like Nyquist I’m not overly concerned about the weather,” said trainer Doug O’Neill, after the favorite jogged twice around the one-mile Pimlico Race Course oval on Friday morning in preparation for the 141st Preakness.

“He had a good gallop yesterday and jogged two miles real composed today. He looked good."

The Preakness has taken on the look of a two-horse race as Stradivari (8-1) and Collector (10-1) are unproven against top-flight competition while the other seven entries are rated either 20-1 or 30-1 in the early odds.

Nyquist has won eight races over five different tracks in positioning himself for a rare unbeaten run through the Triple Crown series for three-year-olds. Only Seattle Slew in 1977 has accomplished that feat.

Nyquist's campaign follows last year's triumph by American Pharoah, who ended a 37-year Triple Crown drought.

“As far as rain or shine, we’re not going to change anything shoeing-wise. He’s going to wear the same shoes he has on, so we’re not concerned about that other than we’d like to have a beautiful day,” said O'Neill.

A perfect scenario as far as Exaggerator trainer Keith Desormeaux is concerned would see a heavy watering of the Pimlico track.

Two of Exaggerator’s three graded victories have come on wet tracks and he finished second in three other soggy tests.

“Where most horses haven’t run on a sloppy track or a quagmire like Santa Anita was that day, at least we know we can do it," said Desormeaux, whose brother Kent will be in the saddle shooting for his third Preakness win.

"If you want to call that an advantage I’ll take it.”

Several of the fresh horses in the race like to run from the front and could pose a traffic problem for fast-starting Nyquist.

Japan-based Lani, who finished ninth in Louisville, is the only other entry from the 20-horse Derby field among the 11 colts that will be saddled up for the Preakness.